Coffee maker for repetitively brewing single cups of fresh coffee

ABSTRACT

Apparatus is provided for brewing coffee a single cup at a time. A longitudinally traversing piston within a cylinder is provided with a transverse bore which registers, successively, with a hopper which fills the bore with coffee grounds, with opposed hot water receiving and dispensing ports, and with fresh water receiving and flushing ports. The hot water utilized in brewing the coffee is received from a hot water chamber which contains a predetermined measure of water and also compression spring means for forcing the water through the grounds at a controlled rate by acting upon a piston which functions as a deflectable wall of the hot water chamber. The hot water chamber is refilled after use and the dispensing piston reset by water under the line pressure which is sufficient to compress the spring to a predetermined position.

United States Patent [1 1 Maxwell Sept. 18, 1973 [76] Inventor: KeatonBruce Maxwell, 3030 N. 7th

St., No. 108, Phoenix, Ariz. 85014 [22] Filed: Aug. 2, 1971 [21] App].No.2 168,432

Related U.S. Application Data [63] Continuation-impart of Ser. No.862,894, Oct. 1,

1969, abandoned.

[52] U.S. Cl. 99/289 [51] Int. Cl. A47j 31/40 [58] Field of Search99/283, 289, 282, 99/302; 222/335 [56] References Cited UNITED STATESPATENTS 2,935,011 5/1960 Perlman 99/283 2,993,430 7/1961 Maxwell 3,089,404 5/ 1 963 Parraga 3,499,506 3/1970 Duman et al 222/335 X FOREIGNPATENTS OR APPLICATIONS 593,616 5/1959 ltaly 99/289 FROM WATER LINEPrimary Examiner-John Petrakes Assistant ExaminerPhilip R. CoeAtt0rney-James H. Phillips et al.

[57] ABSTRACT Apparatus is provided for brewing coffee a single cup at atime. A longitudinally traversing piston within a cylinder is providedwith a transverse bore which registers, successively, with a hopperwhich fills the bore with coffee grounds, with opposed hot waterreceiving and dispensing ports, and with fresh water receiving andflushing ports. The hot water utilized in brewing the coffee is receivedfrom a hot water chamber which contains a predetermined measure of waterand also compression spring means for forcing the water through thegrounds at a controlled rate by acting upon a piston which functions asa deflectable wall of the hot water chamber. The hot water chamber isrefilled after use and the dispensing piston reset by water under theline pressure which is sufficient to compress the spring to apredetermined position.

4 Claims, 4 Drawing Figures PATENTEU SEPI 81973 SHEU 1 OF 2 INVENTORKEATON BRUCE MAXWELL ATTORNEYS PATENTED E I 3.759.162

sum 2 BF 2 ATTORN EYZ INVENTOR mm vm KEATON BRUCE MAXWELL COFFEE MAKERFOR REPETITIVELY BREWING SINGLE CUPS OF FRESH COFFEE This is aContinuation-ln-Part of my copending application, now abandoned, Ser.No. 862,894, filed Oct. 1, 1969, entitled Coffee Maker."

My invention relates to automatic coffee makers and, more specifically,to apparatus for brewing and dispensing-measured amounts of coffee, onemeasure at a time.

In another aspect, my invention relates to certain improvements in anapparatus of the type described.

I have improved the construction and operation of the coffee brewerwhich was the subject of my U.S. Pat. No. 2,993,430, issued July 25,1961. This type of coffee maker is designed principally for use inoffices, stores, factories and other commercial and professional typeestablishments where they are a matter of convenience for both employerand employee. Freshly brewed coffee has an almost universal appeal. Thetaste and aroma of a freshly brewed cup of coffee has never beensatisfactorily duplicated by substitute alternatives such as instant andfreeze dried coffees. The employer,

in an attempt to minimize the loss of productive time occasioned by thecoffee break, has sought to bring the coffee to the employee therebysaving the time consumed by employees in going to a place outside thework area for the purchase and consumption of coffee. Indeed, employershave found it to be good business to furnish the coffee to the employeesat no charge at'the site of employment. In fact, an industry has sprungup in response to this need and there are companies which rent coffeebrewing and dispensing machines to employers for use by employees. Bothemployers who own brewing and dispensing machines and businesses whichsupply such machines to employers on a rental basis are constantlysearching for more efficient machines which are easier to maintain andoperate.

Accordingly, it is an object of this invention to provide an improvementto an existing type of coffee brewing and dispensing machine.

It is a further object of this invention to provide such a machine whichhas fewer moving parts.

Yet another object of this invention is to provide such a machine whichrequires less material and fewer steps in the manufacture thereof.

Other, further, and more specific objects and advantages of theinvention disclosed will become apparent to those skilled inthe art fromthe following description of the invention taken in conjunction with thedrawings in which:

FIG. 1 is a view of the cabinet enclosing the working parts of myinvention;

FIG. 2 is a view of certain internal working parts of my invention,including a hopper, brewing apparatus, piston and piston actuating meansand water heating elements connected to the brewing apparatus;

FIG. 3 is a view of the brewing apparatus wherein a hollow cylinder ispartly in section as are also the ports in the walls thereof; and

FIG. 4 is a view of the water measuring and dispensing apparatus, insection, to illustrate the internal construction thereof.

Briefly, I provide in my invention an elongate hollow cylinder having adry coffee intake port, a hot-waterinlet port, and a fresh-water-intakeport longitudinally spaced along the cylinder and first and secondoutlet ports respectively opposed to said hot water andfreshwater-intake ports. A filter screen is placed in the wall of saidcylinder across the first outlet port. Within the cylinder, 1 provide apiston slidably and sealingly disposed for reciprocating action. Thispiston has a transverse brewing bore for receiving a measured amount ofdry coffee from the coffee intake port. The transverse brewing boreadvances to the hot-water-intake port where, at the commencement of adispensing cycle, it receives hot water under pressure for brewingcoffee and discharging it through the first outlet port. When advancedto the fresh-water-intake port, the transverse brewing bore receivesflushing water through the port which flushes coffee grounds out of thebore through the second outlet. Finally, I utilize means from the priorart for reciprocating the piston within the cylinder to consecutivelyregister the brewing bore with the coffee intake port, with thehot-water-intake port, and with the fresh-water-intake port.

Turning now to the drawings in which the same reference numeralsindicate corresponding elements throughout the various views, FIG. 1shows a coffee cup in position to receive a freshly brewed measure ofcoffee from my invention. The coffee cup is positioned in an aperture 2in the cabinet 1. A door 3 is provided at the top of the cabinet givingaccess to a hopper 4, shown in FIG. 2, containing fresh coffee. Thehopper 4 is preferably made of transparent plastic, and a window 5 isprovided in the case I through which the coffee remaining in the hopper4 may be observed. At one end of the cabinet 1, l have provided a door 6giving access to internal working parts of the invention which mostoften require servicing.

In FIG. 2, inside the cabinet 1,1 have provided a hopper 4 whichcontains fresh coffee. The bottom of the hopper communicates with a drycoffee intake port 12 in the wall of the hollow cylinder 11. Referringalso to FIG. 3, the interior 13 of the hollow cylinder 11 is bored, anda piston 20 is machined to fit the inside bore 14 of the cylinder 1] inclose fitting sliding relationship thereto. The close tolerancedispenses with the necessity for piston rings in the moving parts of myinvention. The piston 20 also has a transverse bore 21, and in the restor initial position, the transverse bore registers with ahot-water-inlet port 22, having received dry coffee from the hopper 4through a dry coffee intake port 12 just prior to completing a previousdispensing cycle. The transverse bore 21 is sized to receive one measureof dry coffee suitable for brewing a single cup of coffee. Liners may beinserted in the transverse bore 21 to reduce the amount of dry coffeecontained and carried by the transverse bore, thereby adjusting thestrength of the coffee.

The mode of operation of the reciprocating mechanism 65, which controlsthe pauses and longitudinal translation of the piston 20, is fullydescribed in my U.S. Pat. No. 2,993,430, issued July 25, 1961. Only thedetail required to fully understand the novel aspect of the improvementsembodied in this invention are set forth in this disclosure.

FIG. 4 illustrates the manner in which the hot water chamber 30 isfilled and emptied and also means for adjusting its capacity. The hotwater chamber 30 is fitted with a piston 32 which functions as adeflectable wall partially defining the interior, and hence the capacityof the chamber. The piston 32 has an upwardly extendin'g stem portion 33of smaller diameter than the piston.

A compression spring 34 is concentrically disposed about the stem andbears upon the upper shoulder 35 of the piston 32 and on the ceiling 36of the hot water chamber 30, thus biasing the piston 32 downwardly. Thestem 33 of the piston 32 protrudes upwardly through an aperture 37 inthe ceiling 36 of the chamber 30 into a sleeve 38 which fits into theaperture 37 and encloses the upper portion of the stem 33. Referringagain to FIG. 2, it will be observed that water from a line source 43 inintroduced under pressure into a preheating chamber 45. ln a firstposition, the double solenoid valve 41 permits communication between theoutlet conduit 50 of the preheating chamber 45 and the inlet conduit 42to the hot water chamber 30. In this position, the pressure of the waterfrom the line raises the piston 32, FIG. 4, until the upper portion 51of the stem 33 of the piston 32 abutts the plunger 52 of a switch 53 toactuate the solenoid of the solenoid operated valve 41 and cut off theintroduction of water into the chamber 30. As the piston 32 is forcedupwardly, the upper surface 35 abutts the angled plunger surface 54 of aspring loaded solenoid 55 and forces it radially outwardly. The plunger52 of the switch 53 is positioned to actuate the switch 53 just afterthe lower edge of the piston 32 clears the plunger 54 which thereuponsprings radially inwardly to hold the piston 32 in the cocked position.it will be observed that the capacity of the hot water chamber 30 can beadjusted by correspondingly adjusting the vertical positions of theplungers 52 and 54.

As the water is held in the hot water chamber 30, the electrical coil 44quickly brings the water to dispensing temperature if it has not hadtime to reach that temperature while in the preheating chamber 45. Boththe coils 44 and 46 may be controllably energized by conventionalthermostat means, not shown, to insure that the water is dispensed atthe proper temperature.

A dispensing cycle is initiated by closing the switch 56, which may bemanually or coin operated, thereby closing the circuit between theelectrical line and the solenoid-operated valve 40 through normallyclosed contacts 59 of a switch 57. Simultaneously, the solenoid 55 isactuated to retract the plunger 54. As a result, the piston 32 movesdownwardly under the influence of the compression spring 34 forcing thehot water through the solenoid operated valve 40 and through thehot-water-inlet port 22 to discharge the water for brewing purposes intothe transverse bore 21. The brewed liquid coffee is then dischargedthrough the outlet port 23 into any suitable container for receiving thefreshly brewed coffee. As the piston 32 moves downwardly,it abuttsinwardly projecting stop members 58 which limit its downward travel. Inthis lowermost position, the switch 57 is actuated to open the circuitbetween the solenoid-operated valve 40 and the power line, therebypermitting the valve to close to stop the discharge of water. To preventthe coffee grounds from being discharged with the freshly brewed coffee,a filter screen 24 is recessed in the wall of the cylinder 11 inregistration with the first outlet port 23.

Simultaneously with the actuation of normally closed contacts 59 of theswitch 57, normally open contacts 60 are closed to provide energizationto one of the solenoids on the double valve 41 permitting preheatedwater to flow from the preheating chamber 45 into the hot water chamber30 to raise the piston 32 and recock it with a charge of brewing wateras previously described. In the meantime, the piston 20 moves to thegrounds flushing position under the influence of the reciprocatingmechanism at which point, as best shown in FIG. 3, the plunger 63 of aswitch 64 is actuated to admit fresh water through an inlet 61 and outan outlet 66 to the intake port 25 thereby flushing the coffee groundsfrom the registered transverse bore 21 through the second outlet port26. In order to facilitate discharge of the coffee grounds from thetransverse bore 21, as illustrated in the drawings, the bore is taperedoutwardly from the inlet to the outlet thereof. Thus, when the piston 20is moved to its fully extended position, the tapered transverse bore 21is moved into position with the second outlet port 26 and flushing waterentering the second water intake port 25 effectively displaces thecoffee grounds from the transverse bore 21, flushing them into thesecond outlet port 26.

Subsequently, under the influence of the reciprocating mechanism 65, thepiston 20 is withdrawn until the longitudinal bore 21 is registered withthe dry coffee intake port 12 of the coffee hopper 4 to receive a chargeof fresh dry coffee after which the piston 20 advances to a position ofregistration with the ports 22 and 23 to await the initiation of anotherdispensing cycle effected described.

While the principles of the invention have now been made clear in anillustrative embodiment, there will be immediately obvious to thoseskilled in the art many modifications of structure, arrangement,proportions, the elements, materials, and components, used in thepractice of the invention which are particularly adapted for specificenvironments and operating requirements without departing from thoseprinciples.

I claim:

1. A machine for automatically brewing and dispensing one measure ofcoffee at a time, comprising:

A. an elongate hollow cylinder having a dry coffee intake port, a hotwater inlet port, and a fresh water inlet port longitudinally spacedalong the cylinder; first and second outlet ports respectively opposedto said hot water and said fresh water inlet ports;

B. a hot water measuring and dispensing chamber having an outletcommunicating with said hot water inlet port; said hot water chamberhaving a resiliently deflectable wall movably responsive to waterpressure internally of said hot water chamber; said wall tending toexpel hot water outwardly through said outlet of said chamber; said hotwater chamber having a water supply replenishing inlet communicatingwith the interior thereof;

C. first electrical heating means in direct heatconducting relationshipwith said hot water chamber to heat the water therein and maintain thetemperature of the water therein at a predetermined level;

D. an inlet shutoff control valve in liquid communication with aconventional line source of water under pressure and disposed toselectively admit water to flow from the source into said chamber inletafter a charge of water has been expelled therefrom;

E. an outlet shutoff control valve communicating with said outlet ofsaid hot water chamber and disposed to pass hot water from said chamberoutlet into said hot water inlet port;

F. a piston slidably sealingly disposed for reciprocating action withinsaid cylinder, and means for reciprocating said piston within saidcylinder to consecutively register said brewing bore with said hot waterinlet port, with said water inlet port, and with said coffee intakeport;

G. said piston having a transverse brewing bore for serially receiving ameasured amount of dry coffee from the said coffee intake port,receiving hot water under pressure from said hot water inlet port forbrewing fresh coffee and discharging the same through the first outletport, and receiving flushing water through said fresh water inlet portfor flushing coffee grounds out of said bore through said second outlet.

2. The brewing and dispensing machine of claim 1 in which saiddeflectable wall comprises a moveable piston within said chamber, saidpiston being biased toward said outlet of said chamber by compressionspring means.

3. The brewing and dispensing machine of claim 2 which further includesmeans responsive to a predetermined translation distance of said pistonfrom said outlet of said chamber under the influence of water pressurefrom the source to cut off flow therefrom, and latching means forholding said piston at a predetermined distance from said outlet of saidchamber whereby a dispensing cycle may be instituted by unlatching saidlatching means thus permitting said piston to move toward said outlet ofsaid chamber to push the hot water through the coffee grounds at apressure and rate determined by said compression spring.

4. The brewing and dispensing means of claim 3 which further includes awater preheating chamber having an inlet connected to the source and anoutlet connected to said water supply replenishing inlet of said hotwater chamber, and second electrical heating means in direct heatconducting relationship with said preheating chamber to heat the watertherein and maintain the temperature of the water therein at apredetermined level.

1. A machine for automatically brewing and dispensing one measure ofcoffee at a time, comprising: A. an elongate hollow cylinder having adry coffee intake port, a hot water inlet port, and a fresh water inletport longitudinally spaced along the cylinder; first and second outletports respectively opposed to said hot water and said fresh water inletports; B. a hot water measuring and dispensing chamber having an outletcommunicating with said hot water inlet port; said hot water chamberhaving a resiliently deflectable wall movably responsive to waterpressure internally of said hot water chamber; said wall tending toexpel hot water outwardly through said outlet of said chamber; said hotwater chamber having a water supply replenishing inlet communicatingwith the interior thereof; C. first electrical heating means in directheat-conducting relationship with said hot water chamber to heat thewater therein and maintain the temperature of the water therein at apredetermined level; D. an inlet shutoff control valve in liquidcommunication with a conventional line source of water under pressureand disposed to selectively admit water to flow from the source intosaid chamber inlet after a charge of water has been expelled therefrom;E. an outlet shutoff control valve communicating with said outlet ofsaid hot water chamber and disposed to pass hot water from said chamberoutlet into said hot water inlet port; F. a piston slidably sealinglydisposed for reciprocating action within said cylinder, and means forreciprocating said piston within said cylinder to consecutively registersaid brewing bore with said hot water inlet port, with said water inletport, and with said coffee intake port; G. said piston having atransverse brewing bore for serially receiving a measured amount of drycoffee from the said coffee intake port, receiving hot water underpressure from said hot water inlet port for brewing fresh coffee anddischarging the same through the first outlet port, and receivingflushing water through said fresh water inlet port for flushing coffeegrounds out of said bore through said second outlet.
 2. The brewing anddispensing machine of claim 1 in which said deflectable wall comprises amoveable piston within said chamber, said piston being biased towardsaid outlet of said chamber by compression spring means.
 3. The brewingand dispensing machine of claim 2 which further includes meansresponsive to a predetermined translation distance of said piston fromsaid outlet of said chamber under the influence of water pressure fromthe source to cut off flow therefrom, and latching means for holdingsaid piston at a predetermined distance from said outlet of said chamberwhereby a dispensing cycle may be instituted by unlatching said latchingmeans thus permitting said piston to move toward said outlet of saidchamber to push the hot water through the coffee grounds at a pressureand rate determined by said compression spring.
 4. The brewing anddispensing means of claim 3 which further includes a water preheatingchamber having an inlet connected to the source and an outlet connectedto said water supply replenishing inlet of said hot water chamber, andsecond electrical heating means in direct heat conducting relationshipwith said preheating chamber to heat the water therein and maintain thetemperature of the water therein at a predetermined level.